Scientists now recognize that the probability of HIV infection is influenced by social, structural and environmental processes that influence individual behavior and vulnerability to infection and that networks are an important part of the risk/resilience environment. Measurement of network characteristics is key to understanding the potential for an epidemic to occur in any group and to identifying intervention points, yet to date, sociometric network studies of Latino migrants are lacking. The goal of this research is to explore the mechanisms of HIV/STI risk/resilience among Latino migrant men in a pre-epidemic phase, with a focus on the effects of the social environment, in particular, drug and sex networks. There are three specific aims: Aim 1: To describe facilitators and obstacles to conducting network informed research among Latino migrant workers to inform future larger studies, Aim 2: To describe the configuration, HIV infection status, geospatial, contextual, and behavioral characteristics of the risk networks of Latino migrant men who do and do not use drugs, and Aim 3: To examine the contribution of drug and sexual networks on the HIV risk and resiliency of migrant workers. PUBLIC HEALTH RELEVANCE: This study will pioneer the use of sociometric risk analysis among Latino migrant workers in a new receiving community to examine their risk and resilience for HIV/STI and drug use. Should this technique be both feasible and useful, our data will provide essential pilot and a road map for conducting sociometric research for this target group and other migrant groups in pre-HIV epidemic phases.